ABSTRACT ? Project 1 Despite numerous studies demonstrating the elevated risk of minorities for environmental toxicant exposures and adverse birth, health, and developmental outcomes, no birth cohorts have characterized exposures among minorities in the US Southeast, which are likely distinct due to differences in climate, housing, population and traffic density, culture, and racial/ethnic composition. Among the most pronounced of health disparities is in the rate of preterm birth (birth < 37 weeks gestation), an important predictor of infant health and neurodevelopment. Compared to those of other race/ethnicities, African Americans (AA), particularly those of the metropolitan Southeast, experience markedly elevated rates of preterm birth. While AA race is a strong predictor of shortened gestation, within-race variation remains poorly understood. Growing evidence supports that aspects of the prenatal and postnatal exposome ? exogenous environmental exposures and endogenous microbiome and metabolic processes ? influence birth outcomes and neurodevelopment through complex relationships. For example, the microbiome plays a role in the presystemic transformation of environmental toxicants and, conversely, environmental exposures may perturb the microbiome. Today little is known about the exogenous and endogenous exposures of AA mother-infant pairs or how they combine to affect infant health and development because prospective studies characterizing exposures and how they influence pregnancy and infant health are scarce. Gaining a better understanding of the complex relationships between the exogenous environment and the endogenous microbiome may help to explain inter-individual susceptibility to environmental exposures. The proposed study will fill existing knowledge gaps by leverage resources of two pillar studies: (1) Subjects and data collected from the socioeconomically diverse cohort of pregnant AA women participating in our recently initiated 5-year study (Parent Study, R01 NR014800) assessing the maternal prenatal microbiome as predictive of birth outcomes; (2) Analytic and bioinformatic resources of Emory University?s NIH-funded Human Exposome Research Center (HERCULES; P30 ES019776). For a subset of the existing cohort from the Parent Study (N=300 mother-infant pairs), the proposed study will add prenatal and postnatal environmental exposure assessment data (to phthalates, bisphenol A, brominated flame retardants, pesticides, parabens, air pollutants) that will provide both a better understanding of the range of fetal and early life exposures faced by AA children and an opportunity to assess whether these prenatal exposures influence birth outcomes. The success of this research is supported by a team representing expertise in exposure assessment science, maternal-child health, epidemiology and informatics; the overlap of key personnel for the proposed study and the on-going Parent Study; and support from Emory University?s HERCULES Exposome Research Center and its Translational Science Institute (CTSA award # NIH UL1TR000454).